Wow, my first post that's frontpaged and it's the one I put the least effort into. I've at least fixed the noise colour bleed now.
This technique does not do any file compression as it's a transformation applied to the image in the browser (though screenshots of the output would be smaller than the source)
(The linked web app doesn’t work on mobile in portrait mode, sorry!)
The biggest issue with this trick is that different engines calculate the filters differently, thus turning an okay-ish image into something that looks like a glitch.
On finnicky engines, I think if I were to seriously implement this for a project that needed to support arbitrary images, I'd do the dithering server side (assuming it's possible to develop some heuristics to select the correct transformation based on image type (text, low contrast, blurry, etc)), serve those to users, and allow them to customize the colouring filters. That way the dithering looks as good as it can per image, but it can then still be stylized to a user's preferences.
Hm, for this - yes I think it would make sense. That being said there are libraries that apply proper dithering without relying on SVG filters.
Also, I haven't tested this with canvas which I imagine would be much more consistent.
If I were to do this... more seriously, I'd keep some parameters exposed in the shortcode/component rendering the dithered images (or data-attrs) so that I could fine-tune them on a case-per-case basis. (I originally wanted to replace the bio photos on my site, like this one https://untested.sonnet.io/notes/wislawa-szymborska/)
There's a ton of articles about this but for something more fun and even better looking I recommend the Coding Train video on Weighted Voronoi Stippling: https://www.youtube.com/watch?v=Bxdt6T_1qgc
My first thought was, this is actually SVG in CSS right? The capabilities of SVG are so underrated.
I don't know how it makes sense that a vector graphics format has a filter format that can be applied to rasterized bitmaps though? Even more weird that I've used them on `<video>` too.
While I appreciate the retro aesthetic effect some blogs and sites use in dithering photographic images, I just don't think it works well on the modern web.
People are using too many different device sizes and device resolutions. Look at an image on a small mobile screen and it's basically converted back to grayscale. Or make the dithering so coarse that it still looks dithered on a phone screen, and it just looks horribly blocky and unclear on a desktop.
I have to admit I don't think it's visually very appealing like that. It looks more like some sort of error/ glitch. Maybe my old Firefox does it weirdly?
If we could get jbig2 native support in browsers we could do monochrome black and white images at ridiculously small file sizes.
A page of sheet music can be as small as 8kb. I'm using a wasm decoder right now, but I could forsee using css filters after the fact to make it look less sharp and aliased
I'd love to see a live preview of the final file size that updates as you change the parameters, maybe debounced by 100ms or so. Although as others mentioned, is this actually proper dithering, seems like the effect of dithering without actually doing it?
It is so wild that this got shared, as I was working on a project that very specifically was hoping to integrate a feature like this. Psyched to try it, I’ll credit the author in the credits of the site I’m building.
This technique does not do any file compression as it's a transformation applied to the image in the browser (though screenshots of the output would be smaller than the source)
For a post on CSS-based noise dithering that I actually polished, there's also https://ikesau.co/blog/making-a-grainy-spotlight-effect-with...
(The linked web app doesn’t work on mobile in portrait mode, sorry!)
The biggest issue with this trick is that different engines calculate the filters differently, thus turning an okay-ish image into something that looks like a glitch.
On finnicky engines, I think if I were to seriously implement this for a project that needed to support arbitrary images, I'd do the dithering server side (assuming it's possible to develop some heuristics to select the correct transformation based on image type (text, low contrast, blurry, etc)), serve those to users, and allow them to customize the colouring filters. That way the dithering looks as good as it can per image, but it can then still be stylized to a user's preferences.
Also, I haven't tested this with canvas which I imagine would be much more consistent.
If I were to do this... more seriously, I'd keep some parameters exposed in the shortcode/component rendering the dithered images (or data-attrs) so that I could fine-tune them on a case-per-case basis. (I originally wanted to replace the bio photos on my site, like this one https://untested.sonnet.io/notes/wislawa-szymborska/)
There's a ton of articles about this but for something more fun and even better looking I recommend the Coding Train video on Weighted Voronoi Stippling: https://www.youtube.com/watch?v=Bxdt6T_1qgc
I have dabbled with some dithering algorithms and while this is way faster than my naive js implementations, this looks pretty bad
I think the noise is also way too 'soft'. At high frequencies it just becomes near-uniform gray so it barely affects the thresholding.
https://www.wsj.com/articles/whats-in-a-hedcut-depends-how-i...
https://developer.mozilla.org/en-US/docs/Web/SVG/Reference/E...
I don't know how it makes sense that a vector graphics format has a filter format that can be applied to rasterized bitmaps though? Even more weird that I've used them on `<video>` too.
People are using too many different device sizes and device resolutions. Look at an image on a small mobile screen and it's basically converted back to grayscale. Or make the dithering so coarse that it still looks dithered on a phone screen, and it just looks horribly blocky and unclear on a desktop.
A page of sheet music can be as small as 8kb. I'm using a wasm decoder right now, but I could forsee using css filters after the fact to make it look less sharp and aliased